In the past decades, as an important way for C–H bond activation, transition-metal-catalyzed C–H insertion reactions have achieved great progress and been widely used in organic synthesis. The selectivity of C–H insertions is simultaneously influenced by both of the steric effect and the electronic effect. In general, the C–H bonds at allylic or benzylic sites or at α-position of heteroatoms have higher electron density, which benefits the insertion reactions. On the contrary, the C–H bonds at α position to electron withdrawing groups have lower electron density, which are unfavorable for insertion reactions.

In this context, efficient carbenoid insertion into high polar C–H bonds of malonates and β-carbonyl esters has been developed by using CuCN-PCy3 catalyst in the presence of NaBArF. This novel system exhibits not only high catalytic activity but also excellent chemoselectivity in the reaction. Under mild reaction conditions, the C–H bond insertions proceeded smoothly to produce multi-functionalized C–H insertion products with high yield. Furthermore, the system was successfully applied for the first time to C-H bond insertions of acetylacetone, β-cyano ketone, malononitrile with good results. This work not only expands the substrate scopes for the C-H bond insertion reactions, but also provids a simple and efficient route for synthesis of multi-functionalized compounds such as succinate derivatives.

According to the experimental results, we discussed the mechanism of copper carbenoid insertion into high polar C–H bonds, and gave explanation for the formation of by-products.

A variety of important multi-functionalized organic synthons were also prepared from the C–H bond insertion products.

89 new compounds were synthesized in this thesis. They were identified by 1H NMR, 13C NMR, MS, HRMS or elemental analysis. Some compounds were directly confirmed by X-ray diffraction.